Golf is a game which naturally fosters in the golfer a keen desire to improve. As a result, the typical golfer is constantly searching for techniques and methods by which to improve, perfect, or "groove" the desired golf swing or golf stroke.
The physics involved in hitting a golf ball are relatively simple. Ignoring the effects of wind and the behavior of the club head and golf ball at impact, the flight of the golf ball, and hence the distance and accuracy of the golf shot, is primarily controlled by three factors. These factors are the alignment of the club face of the golf club at impact, the direction of movement of the club head of the golf club at impact, and the speed of the club head at impact. This is true for both full-swing golf shots and for the putting stroke which is used to accurately roll the ball across the putting green and into the hole.
Therefore, when putting it is desirable to accurately control the alignment of the club face of the putter and the direction of movement of the club head at the point of impact. Further, because the putting stroke will normally be used on each golf hole played by the golfer, it is particularly desirable to control these factors in a consistent manner, also known as "grooving" the putting stroke.
There are a variety of devices which have been developed to assist the golfer in aligning the golfer's feet and club head as well as devices to help groove the proper swing path. One category of such devices includes those with one or two guide rails placed adjacent to the golf ball. The golfer can stroke the club along the guide rails to practice a straight-back and straight-through putting stroke. Unfortunately, the guide rails are not typically adjustable in their spaced-apart positions from each other. Such adjustment is desirable because golf clubs, particularly putters, come in a variety of differently-sized dub heads. In order to tightly constrain the moving club head to be between the two guide rails, it is necessary to provide adjustability of the positions of the guide rails. A device which does provide adjustable guide rails involves loosening a screw and adjusting a housing relative to another housing and then re-tightening the screw. Such an arrangement is cumbersome and inconvenient.
Other devices which assist the golfer in the alignment of the club head have included laser light sources associated with the golf club and indicating the direction in which the club face is pointed. One drawback of all such devices is the requirement that the golfer cannot use the golfer's own personal putter without modification. Each of the devices either requires a specialized, custom putter incorporating the device or requires a modification or attachment to the golfer's own putter. Such devices do not accommodate the golfer's desire to practice with their own putter in an unmodified fashion. Golf clubs, and particularly putters, come in a variety of lengths, weights, and distributions of weight along the golf club. Further, the shape of the club head provides an aesthetic appearance which may instill confidence in the golfer. All of these factors cause a golfer to become comfortable with their own putter and less likely to use or feel comfortable with a specialized, custom putter or even with their own putter if modified to change the appearance, shape, and/or weight distribution.
A further disadvantage of these devices is the fact that the direction of the light beam projected from the light source is dependent on the directional alignment of the dub face of the putter. Since the putter is held in the hands of the golfer and is moved during the putting stroke, the light beam tends to move dramatically, resulting in a moving light spot which is hard to follow. Further, even when the light spot is stationary and perceptible, it indicates the directional alignment of the club face and not of the desired target path of the golf ball.
In summary, none of these devices provides the desired training environment. Either the devices are inconvenient and cumbersome or they do not provide the desired indications.